Canada’s last fully intact Arctic ice shelf collapses

Canada’s last fully intact Arctic ice shelf collapses

SOURCE: Reuters DATE: August 6, 2020 SNIP: The last fully intact ice shelf in the Canadian Arctic has collapsed, losing more than 40% of its area in just two days at the end of July, researchers said on Thursday. The Milne Ice Shelf is at the fringe of Ellesmere Island, in the sparsely populated northern Canadian territory of Nunavut. “Above normal air temperatures, offshore winds and open water in front of the ice shelf are all part of the recipe for ice shelf break up,” the Canadian Ice Service said on Twitter when it announced the loss on Sunday. “Entire cities are that size. These are big pieces of ice,” said Luke Copland, a glaciologist at the University of Ottawa who was part of the research team studying the Milne Ice Shelf. The shelf’s area shrank by about 80 square kilometers. By comparison, the island of Manhattan in New York covers roughly 60 square kilometers. “This was the largest remaining intact ice shelf, and it’s disintegrated, basically,” Copland said. The Arctic has been warming at twice the global rate for the last 30 years, due to a process known as Arctic amplification. But this year, temperatures in the polar region have been intense. The polar sea ice hit its lowest extent for July in 40 years. Record heat and wildfires have scorched Siberian Russia. Summer in the Canadian Arctic this year in particular has been 5 degrees Celsius above the 30-year average, Copland said. That has threatened smaller ice caps, which can melt quickly because they do not have the bulk that larger glaciers have to stay cold. As...
Sea level fears as more of giant Antarctic glacier floating than thought

Sea level fears as more of giant Antarctic glacier floating than thought

SOURCE: Agence France Presse DATE: March 20, 2018 SNIP: More of a giant France-sized glacier in Antarctica is floating on the ocean than previously thought, scientists said Tuesday, raising fears it could melt faster as the climate warms and have a dramatic impact on rising sea-levels. The Totten Glacier is one of the fastest-flowing and largest glaciers in Antarctica with scientists keen to keep a close eye on how it melts given the enormous amount of water it could potentially unleash. Using artificially created seismic waves that help scientists see through the ice, researchers have discovered that more of the Totten Glacier floats on the ocean than initially thought. The findings are important because recent studies have shown the Totten Glacier’s underbelly is already being eroded by warm, salty sea water flowing hundreds of kilometres inland after passing through underwater “gateways”. As it does, the portion of the glacier resting on water rather than rock increases, accelerating the pace of...
‘Scars’ left by icebergs record West Antarctic ice retreat

‘Scars’ left by icebergs record West Antarctic ice retreat

SOURCE: University of Cambridge Research and Washington Post DATE: October 25, 2017 SNIP: Thousands of marks on the Antarctic seafloor, caused by icebergs which broke free from glaciers more than ten thousand years ago, show how part of the Antarctic Ice Sheet retreated rapidly at the end of the last ice age as it balanced precariously on sloping ground and became unstable. Today, as the global climate continues to warm, rapid and sustained retreat may be close to happening again and could trigger runaway ice retreat into the interior of the continent, which in turn would cause sea levels to rise even faster than currently projected. “Ice-cliff collapse has been debated as a theoretical process that might cause West Antarctic Ice Sheet retreat to accelerate in the future,” said co-author Dr Robert Larter, from the British Antarctic Survey. “Our observations confirm that this process is real and that it occurred about 12,000 years ago, resulting in rapid retreat of the ice sheet into Pine Island Bay.” Today, the two glaciers are getting ever closer to the point where they may become unstable, resulting once again in rapid ice...
Rift Speeds Up Across Antarctic Ice Shelf

Rift Speeds Up Across Antarctic Ice Shelf

SOURCE: Climate Central DATE: September 30, 2016 AUTHOR: Andrea Thompson SNIP: As the sun reemerged over the Antarctic horizon in August after the long, dark austral winter, satellites could once again peer at a rift that has been wending its way across the white expanse of the Larsen C Ice Shelf on the eastern side of the Antarctic Peninsula. To the surprise of scientists, satellite images revealed that the fissure had grown by about 13 miles over just a few months — much faster than its previous pace. …the first post-winter satellite images from late August showed that this rift had managed to break across that zone and streak ahead; it now reaches about halfway across the ice shelf, parallel to its front. When Daniela Jansen, a glaciologist at the Alfred Wegner Institute in Germany, first looked at those photos, “I was really surprised how fast this was developing,” she...